Immobilized Lipase Catalyzed Synthesis Of Vitamin A Plamitate

As one of important types of additives, Vitamin A palmitate is widely used in cosmetics, medicine and other chemical industries. Enzyme-catalyzed production of vitamin A palmitate boasts many advantages such as mild reactions, good catalytic effect and low energy consumption. In this paper, The method of changing substrate was investigated.The synthesis of Vitamin A plamitate in organic solvent with Vitamin A acetate and ethyl palmitate with immobilized lipase from Candida sp. was studied. The influences of solvent, the molar ratio of substrates, the reaction temperature and time, and the water concentration were optimized and the best result was obtained by transesterification from0.100g Vitamin A acetate and0.433g ethyl palmitic, at30℃, in10mL petroleum ether, containing0.2%of water(V/V), with1.1g lipase. In these conditions, the yield of Vitamin A palmitate reached83%in12h. The immobilized lipase was reused about5batches.The synthesis of Vitamin A plamitate in organic solvent with Vitamin A and palmitate was studied. The method was two steps. First, Vitamin A acetate was hydrolysed and become Vitamin A by chemical method. Then, Vitamin A plamitate was synthesized with Vitamin A and palmitate with immobilized lipase. The molar ratio of substrates, the reaction temperature and time, the mount of immobilized lipase, and the mount of absorbent were optimized and the best result was obtained by esterification from0.5mmol Vitamin A and0.128g palmitic, at30℃, in10mL petroleum ether, with0.100g lipase, with0.300g silica gel. In these conditions, the yield of Vitamin A palmitate reached90%in1h. The immobilized lipase was reused about50batches and the yield of Vitamin A palmitate remained88%.Scale-up of the process was studied. Designed the circulation reactor and the packed bed reactor. The yield of Vitamin A palmitate reached90%in2h with the circulation reactor. The Vitamin A palmitate was producted continuously with the packed bed reactor. The yield of Vitamin A palmitate reached90%. Production capability was133g/h.